25
the correct design of the pumps, fittings, piping and buffer tank used and
the safety components. We recommend minimum nominal dimensions for
heating pipes of: copper pipes: 22x1.0 mm or steel pipe: ¾". For cold water
pipes a nominal pipe size (copper pipe) of 15x1.0 and a flow pressure of 2.0
bar are sufficient for safe operation. Possible variant for integration of the
ambiente a4 H
2
O into a heating system.
A
Temperature sensor for thermal discharge safety device ½¨ IG
B
Temperature sensor for thermostatic switch ½¨ IG
C
Return ¾¨ IG
D
Flow ¾¨ IG
E
Safety valve 2.50 - 3.0 bar
F
Connecting pipe vent
G
Pump thermostatic switch (e.g. Afriso, GTK)
H
Thermostatic valve
I
Heating system hydraulic connection
J
Buffer tank
K
Load unit (e.g. ESBE, model LTC 141)
L
Circulating pump
M
Filling and emptying fitting
N
Expansion tank
O
Thermal discharge safety device (e.g. Watts, STS 20/200)
P
Open drain, e.g. into wastewater system
Q
Safety heat exchanger drain ½¨ IG
R
Safety heat exchanger inlet ½¨ IG
S
Heat exchanger vent
3
/
8
¨
T
Non-return valve
However, the pipes should be dimensioned by the specialist firm, taking
local conditions into account.
The ambiente a4 H
2
O can be integrated with reference to
Figure 14
.
A buffer tank must be included. The buffer tank volume should be calculated
according to BImSchV 1 and 2 (see „2.2. Technical Data“ on page 7).
This specifies that 55 litres of buffer tank volume must be provided per kW
water output. For the ambiente a4 H
2
O that means: 5.7 kW x 55L/kW = 341L.
As this is not a standard size available on the market, the next largest buffer
tank with a capacity of 500 litres should be selected. The following sample
calculation may be helpful for dimensioning the buffer tank:
The following assumptions have been made:
• Buffer tank size: 500 litres (approx. 500 kg water)
• Initial water temperature in buffer tank: 40°C
• Final water temperature in buffer tank: 70°C
• Temperature differential 30°C (corresponds to 30 K)
•
No heat is drawn from the tank while it is being heated by the
ambiente a4 H
2
O
Q = c p × m × ∆t
Q = 4,187 kJ × 500 kg × 30 K
Q = 62805 kJ
kg × K
